Biodiversity of woody species in oak woodlands of southern Spain and northern Morocco

Three biodiversity parameters - species richness, endemic species richness and taxonomic singularity - have been evaluated for the woody understorey o f oak woodlands on sandstone-derived substrates, on both sides of the Strai t of Gibraltar. There is a similarity in floristic composition and ecologic al distribution of woody plant communities across the Strait. Nevertheless, we have detected significant differences. These include a general reductio n in species richness, number of endemic species and taxonomic singularity (at the community level), and a greater abundance of widespread, generalist species, on the southern side (Moroccan) communities, as compared to the n orth (Spanish ones). We interpret these differences as partly caused by the contrasting management of woodlands, with higher slashing and browsing pre ssure in Morocco. (C) 1999 Elsevier Science B.V. All rights reserved.